Present invention, directed to the field of electromagnetic rotatory motors, employs an ac power source and a tangential twin-row bristle stator and a nonmagnetic rotor having an armature receiving ac from the stator through capacitive conduction, with wide torque capability.
In case of a rotatory ac electric motor, the air gap between the stator and the rotor results in significant weakening of effective magnetic flux density in the magnetic circuit of the motor, resulting in high magnetizing currents and limited peak torque. Further, due to the frequency-pole-rpm relationship in the motor, peak torque cannot increase without increasing either the stack length or the stack diameter of the motor, which results in an increased motor weight. Extremely high power-to-weight ratios are needed to implement electric propulsion in electrical vehicles and aviation.
All of the existing electrically powered motion-giving technologies employ a rotatory or linear moving electromagnetic field. Especially, the linear movement of the electromagnetic field is either externally induced or self-induced by the linear translatory motion of a current-carrying armature along a linear twin stator. The twin stator is often schematically drawn as parallel rails to ease the theoretical understanding. However, the easy visualization as rails has impeded the evolution of technology in the present field, as many designers began concept making from a vivid visualization of parallel rails carrying a current-carrying armature and busied themselves with solving ancillary problems. Problems associated with long parallel rails were partially solved with segmental and chevron-shaped nested segmental rails; the employment of chevron-shaped nested segmental rails as inductive storage means was a step towards reducing rail-lengthwise voltage drops; but it also meant supplying very high peak currents pulses to the inductive storage means. However, either a contact-less and tribo-efficient or arcless and smooth current-delivery method to the current carrying armature can solve many existing problems together with the development of a high-power density ac electric motor, as discussed in the preceding paragraph. At present, a device popularly called ball bearing motor finds limited interest by some enthusiasts. Ball bearing motor has very little practical value, as it only demonstrates a unique and controversially understood mechanism for an alternative electric motor. However, in spite of the various claims to the special nature of the ball bearing motor, it is a rotary variant of so-called EM railgun with all the associated problems, such as, arcing and excessive heating.